Opening device for cans



June 5, 1934. K. QMSTED 1,961,909

OPENING-DEVICE FOR CANS Filed Nov. 11, 1932 Fig.2- Fig-5- \I G W H MMH WWW w n m nml 1 null" KAARE OMSTED INVENTOR immwa ATTORNEYS Patented June 5, 1934 UNITED STATES 1,961,909 I OPENING DEVICE FOR CANS Kaare Omsted, Oslo, Norway PA ENT orriee Application November 11, 1932', Serial No. 642,208 1 4 In Norway November 14, 1931 Claims; (01. 220-52) My invention relates to opening cans.

For opening of cans by tearing off the cover along weakened lines in the cover or in the f 5. walls of the can proper keys are commonly used which engage a tearing tongue or a pin and which'by a rolling movement tear off a sheet strip or the entire cover along the weakened lines.

devices for .10 According to the present invention, a pin is used for retaining the key, said pin being so located relatively to the weakened line that a shearing action (as distinguished from a tearing or bending action) from the first start ofthe .,15 opening operation is established.

Other important features or" the invention will be explained in connection with the description of an embodiment of theinvention, which is shown in the accompanying drawing.

" Figs. 1 and 2 illustrate a part of the can cover with the opening device, Fig. 1 before the open ing operation and Fig. 2 after the key having been turned a little.

Fig. 3 is a plan view of the sheet wall with the weakened lines and the pin hole.

Fig. 4 is an enlarged sectional View of the preferred embodiment of the opening pin with a cross section of the key shown in dotted lines.

Figs. 5 and 6 are views of a preferred form '30 of the key.

Figs. 7 and 8 illustrate the use of the invention for a special purpose.

Fig. 9 shows a rubber plug.

As shown in the drawing, the pin A comprises a head B and on the upper side of the sheet wall, a shoulder C of about the same diameter. The pin hole is placed between the weakened lines in such a manner that the head B by the rolling-up (Fig. 2) acts as shears 01 a cutting A0 knife in the weakened line, whereby this action is ensured by means of the shouder C. It is preferable to provide the weakened lines (Fig. 3) in such a manner that the diameter of the pin and its head have small dimensions so that only a small initial opening its required to start the opening operation.

The shoulder C also serves the purpose of obtaining a sealed connection between the pin and the sheet wall. As shown in Fig. 4, the shoulder .50; is preferably formed by a ring which is pressed on to the pin. By the pressing operation by means of press tool with conical press faces the ring is compressed as well axially as radially, forming conical faces D, so that the ring enters into the pin material (as shown at E).

The key may have any suitable form. It is, however, preferable to. use a key of the form shown in Fig. 5. By bending together a piece of metal wire G, a slot H is formed between the branches. 1

The wire ends abut freely at I. The part K may thus be somewhat resilient, whereby the key is" easily placed on the pin (Fig. 6). At the place where the key engagesthe pin it is'advisable to give the key such a cross sectional 5 form that faces are provided (Fig. 4) which bear against the-shoulder C and the upper head F of. the pin.

An important thing for a practical carrying out and use of the invention is that the key at 7 the beginning of the rolling movement does not press against the tin body, but has secure bearing above the same, that is to say against the shoulder of the pin.

I may also use my invention for the purpose of forming a hole in the tin cover through which the liquid contents of a tin for instance milk may be poured out. I have shown in Fig. '7 a tin with a key arranged for this purpose. The drawing is a plan view of part of the top face of '80 the tin. In this case the weakened line is in the form of a circle around the head of the pin, close up to its edge. When the key has been swung outwards and given a turn, it will break out the small circular piece of the tinas shown in Fig. 8.

O is a rubber plug, shown in side view in Fig. 9. It may be used to close the hole broken out by means of the key. The plug is slotted at P, so that it may, as shown in Fig. 7 be placed and held on the handle of the opening key.

What I claim is:

1. In a device for sealing and opening a container of sheet metal having a curved weakened line, the combination, with a pin extending through the sheet metal of said container in spaced proximity to said weakened line and having a head disposed upon the inside of said sheet metal and the edge of said head practically registering with at least a portion of the weakened line, of a collar disposed on said pin upon the outside of the sheet metal of said container with the edge of the collar similarly registering exteriorly with said weakened line, and an expanded portion upon the pin retaining said collar in intimate contact with said pin and said sheet metal and said head with the inside of said sheet metal, there being means for exteriorly engaging said pin and manipulating the same so as to shear through the sheet metal at the weakened line.

2. In a device for sealing and opening a container of sheet metal having a curved weakened line, the combination, with a pin extending through the sheet metal of said container in spaced proximity to said weakened line and having a head disposed upon the inside of said sheet metal and the edge of said head practically registering with at least a portion of the weakened line, of a collar of substantially the same diameter as said head disposed on said pin upon the outsideof thlei sheet metal of said container with the edgeof'f the collar' similarly registering exteriorlywith said w kened line, an expanded portion'u'pon the pin-retaining said collar in intimate contact with said pin and said sheet metal and said head with the inside of said sheet metal, and a projection upon said pin exteriorly of said expanded portion adapted to be engaged by a key for manipulation of said pin so as to shear through the sheet metal at the weakened line.

3. In a device for sealing and opening a container of sheet metal having a curved weakened line, the combination, with a pin extending through the sheet metal of said container in spaced proximity to said weakened line and having a head disposed upon the inside of said sheet metal and the edge of said head practically registering with at least a portion of the weakened line, of a collar disposed on said pin upon the outside of the'sheet metal of said container with the edge of the collar similarly registering exteriorly with said weakened line, an expanded portion upon the pin retaining said collar in intimate contact with said pin and said sheet metal and said head with the inside of said sheet metal, and a projection upon said pin exteriorly of said expanded portion terminating in an exterior head and adapted to be engaged by a key for manipulation of said pin so as to shear through the sheet metal at the weakened line.

4. In a device for sealing and opening a container of sheet metal having a closed weakened line, the combination, with a pin extending outwardly through a perforation in the sheet metal of said container and having a head both disposed against the inside of the sheet metal and practically registering and coinciding with the weakened line therein, of a collar disposed on said pin upon the outside of the sheet metal of said container with the edge of the collar similarly registering exteriorly with said weakened line, an expanded portion upon the pin retaining said collar in intimate contact with said pin and said sheet metal and said head with the inside of said sheet metal, and a projection upon said pin exteriorly of said expanded portion terminating in an exterior head and adapted to be engaged by a key for manipulation of said pin in order to shear through said sheet metal along said weakened line entirely about the collar and inner head of said pin so as to produce an aperture having a geometrical form.

5. A can sealing and opening deviceaccording to claim 1, wherein the exterior collar upon the pin and the interior head of the latter clamp the sheet metal in intimate sealing contact between them, and the expanded portion of the pin is formed to produce the clamping effect by being in forced contact under pressure with said collar and exerting pressure thereon so as to retain the same in contact with the sheet metal and said pin.

KAARE OMSTED. 

